The "systematic faults" are relevant for hardware and software development. These faults, or the resulting risk of damage, can be addressed with preventive actions. Most important attempt to avoid faults is made by a suitable development process.
Reducing the risk of dangerous faults
Well, in reality we see, that there is no absolute safety. There is always a certain residual propability of a fault, and therefore a risk that a system is causing harm. How much this socially accepted residual risk is, depends on the probability a damage occurs and the extent of the damage.